Now I have a question to request ,please lost several minutes.
Q1: How can i split a polygon
now there is a polygon A,when i draw a line, then the polygon split to two (A1,A2).
Q2:How can i merge serveral polygon to one
now there is two or more than two polygons next (A1,A2) ,when I press Ctrl key ,then the polygons all be choiced ,how can I merge then to one(A)
like the picture up pic two ------> pic one